Presence service is a communication service for publishing and distributing presence information. Many people want to obtain presence information of a presence service subscriber. These people include family members and friends of the presence service subscriber or strangers. However, a lot of presence information belongs to privacy of the presence service subscriber. Therefore, the presence service subscriber needs to set up some strategies to publish the presence information. Such strategies to publish the presence information of presence service subscribers are referred to as subscriber configuration information (preference).
In the prior art, configuration information must be set by a presentity client, and there exists no delegation mechanism. Referring to FIG. 1, an existing system includes: a presentity client, a presence server, a watcher client, an XML (extensible Markup Language) document management server (Presence XDMS) and an aggregation proxy. The above components respectively have the following functions.
The presentity client is a presence information source. When the presence information changes, the presentity client sends a publish message to the presence server spontaneously and publishes updated presence information. After processing the publish message (including synthesis, authorization, filtration, etc.), the presence server sends an update notification message to all watcher clients who subscribe to the presence information so that the watcher clients may know the updated presence information.
Based on the existing system, the presentity client may set its configuration information, which includes: (1) modes of publishing the presence information; (2) strategies for publishing different information to different watcher clients; (3) strategies for anonymous watcher clients or unauthenticated watcher clients; (4) strategies for other unspecified subscribers; (5) strategies for a specific watcher client, a specific request or a specific request type; (6) for a watcher client or a watcher client group, strategies defined by a plurality of presentity clients, so that the presence server may know all their presence information, part of their presence information, or other information based totally or in part on their presence information; (7) a mechanism for limiting times a watcher client may retrieve the presence information of a presentity client; (8) default strategies defined by a presentity client and/or an administrator, on each presentity client, each watcher client, each presentity client group or each watcher client group.
The presence server is responsible for receiving a subscription message from a watcher client and determining a subscription result according to preset configuration information of the subscribed presentity client. The presence server is also responsible for receiving a publish message of a presentity client, processing the publish message based on rules (content authorization and filtration) preset by the presentity client or a watcher client, and finally publishing the presence information to the watcher client via an update notification.
The watcher client subscribes to presence information of a presentity client and receives a distributing message from the presence server.
The XML document management server is used to save an authorization list (subscription authorization list, content authorization list, etc.) and/or a group list of presentity clients.
The aggregation proxy is used to have a presentity client or a watcher client interact with a presence server and a presence XDMS to set an authorization list and/or a group list.
Based on the above system, the existing flow for setting the configuration information is as follows:                A presentity client sends a configuration request message for setting its configuration information to an aggregation proxy;        The aggregation proxy forwards the configuration request message to a presence XDMS;        Upon receiving the configuration request message, the presence XDMS sets the configuration information of the presentity client;        The presence XDMS feeds a response message back to the aggregation proxy;        The aggregation proxy feeds the response message back to the presentity client.        
However, in some cases, a presence service subscriber may need a delegation mechanism so that a delegated entity may set the configuration information of the presence service subscriber. For example, the cases may be as follows:
1. The presence service subscriber delegates an application to set the configuration information of the presence service subscriber. The application may be a server for providing a public malicious subscriber list which comes from the complaint of presence service subscribers or is obtained in other ways (data mining). In such a case, the presence service subscriber may delegate the application to set configuration information of the presence service subscriber so that malicious subscribers will be refused to subscribe to the presence information of the presence service subscriber.
2. The presence service subscriber delegates another presence service subscriber to set preference information of the presence service subscriber. For example, subscriber A who is not familiar with its working environment may delegate its colleague to set the preference of subscriber A so as to meet requirements of the working environment.
3. The presence service subscriber is in a game scene. According to game logic, the presence information of the presence service subscriber will be set by a game server so as to meet specific requirements of the game logic. For example, a certain game logic requires that the presence service subscriber can only publish all the game-related presence information to teammates of the presence service subscriber, and the presence service subscriber must publish location-related presence information to its enemies, except when the presence service subscriber is wearing an invisible garment, etc.
Therefore, at present, setting of the configuration information must be performed by a presentity client and cannot be delegated to other entities.
As a result, how to provide a method and a system for setting configuration information of a presentity client in a delegation mode is becoming an urgent technical problem.